Messages in this thread | | | Date | Thu, 16 Jul 2015 22:48:07 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v3 3/8] perf: Add a flags parameter to pmu txn interfaces |
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On Tue, Jul 14, 2015 at 08:01:50PM -0700, Sukadev Bhattiprolu wrote: > +DEFINE_PER_CPU(int, nop_txn_flags); > + > +static int nop_txn_flags_get_and_clear(void) > +{ > + int *flagsp; > + int flags; > + > + flagsp = &get_cpu_var(nop_txn_flags); > + > + flags = *flagsp; > + *flagsp = 0; > + > + put_cpu_var(nop_txn_flags); > + > + return flags; > +} > + > +static void nop_txn_flags_set(int flags) > +{ > + int *flagsp; > + > + flagsp = &get_cpu_var(nop_txn_flags); > + *flagsp = flags; > + put_cpu_var(nop_txn_flags); > +}
That's really horrible, see below:
> +static void perf_pmu_start_txn(struct pmu *pmu, int flags) > { __this_cpu_write(nop_txn_flags, flags); > + > + if (flags & ~PERF_PMU_TXN_ADD) > + return; > + > perf_pmu_disable(pmu); > } > > static int perf_pmu_commit_txn(struct pmu *pmu) > { int flags = __this_cpu_read(nop_txn_flags); __this_cpu_write(nop_txn_flags, 0); > + > + if (flags & ~PERF_PMU_TXN_ADD) > + return 0; > + > perf_pmu_enable(pmu); > return 0; > } > > static void perf_pmu_cancel_txn(struct pmu *pmu) > { int flags = __this_cpu_read(nop_txn_flags); __this_cpu_write(nop_txn_flags, 0); > + > + if (flags & ~PERF_PMU_TXN_ADD) > + return; > + > perf_pmu_enable(pmu); > }
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